*, :after, :before {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html, body, #app, .wrapper {
  height: 100%;
}
body {
  font-family: "Helvetica Neue", "Helvetica", "Microsoft YaHei", "arial", "STHeiTi", "sans-serif";
}
a { 
  text-decoration: none; 
}